This invention relates to a wind deflector for sliding roofs of automobiles, comprising a wind deflector plate situate at the forward edge of a roof opening, which plate is arranged to project above the upper roof surface and be inclined upwardly and outwardly away from the roof opening in the direction opposite to the automobile's direction of forward travel and is adapted on its upper side to generate air drag.
The invention is applicable both to those wind deflector plates which are fixed rigidly to the forward roof opening edge and also to those which are pivotally mounted in the vincinity of the forward edge of the roof opening and are constructed to be lowered below the closed sliding roof.
Wind deflectors are designed to deflect away from above the roof opening the air flow above a travelling automobile when the sliding roof is open, so that, by generating an air flow above the roof opening compared to the relatively stationary ambient air in the interior of the automobile, an air movement is produced which is oriented from the interior of the vehicle outwards and thus provides effective ventilation of the passenger space through fresh air flowing into the automobile via ventilation openings. A disadvantage of such wind deflectors arise, however, from the breakaway of the deflected air flow at the rear edge of those wind deflector plates which project more or less steeply beyond the roof surface. Because of this flow breakway, turbulence is produced at the rear edge of the wind deflector plate, causing annoying wind noise and unpleasant vibrations in the interior of the vehicle, especially during high speed travel.
These disadvantages of wind deflectors are generally well known and so far it has not been possible satisfactorily to overcome them.
In one known wind deflector (DE-PS 23 39 680), the wind deflector has an aerofoil section with its cross-sectional area increasing in the flow direction. The thus shaped wind deflector possesses only a small angle of incidence and is disposed recessed in the roof opening. By this means air drag is intended to be generated on its upper face and thereby produce a quiet flow of wind around the deflector. The disadvantage of this known wind deflector arises from its thickened cross-section which, in the case of pivoting-in wind deflectors, requires a considerable accommodation space, which amongst other things increases the overall depth of the sliding roof construction and thereby reduces the headroom in the interior of the vehicle.
In another known wind deflector (DE-Gm 81 31 939), the wind deflector is equipped, in order to achieve an under-flow, with an upwardly oriented slit aperture extending transversely of the automobile and located substantially outside of the roof contour when the deflector is raised. By means of this slit opening, an under-flow is intended to be produced, which leads to a ventilation of the dead space behind the wind deflector, so that the suction in this region is reduced. This known wind deflector also has a relatively thickened cross-section, so that the aforementioned disadvantages again arise.
Accordingly, the present invention seeks to provide a wind deflector which, in spite of its construction as a relatively thin and thus space-saving leaf profile, generates effective drag on its upper face and thus produced a considerable reduction in wind noise and vibration.